Method of and apparatus for treating the inner surface of tubular bodies with blasts



W. ECKLER March 27, 1934.

METHOD OF AND APPARATUS FOR TREATING THE INNER SURFACE OF TUBULAR BODIES WITH BLASTS Filed Aug. 31, 1933 Fiyi? v VVENTR wai/f Patented Mar. 27, 1934 :METHOD OF AND APPARATUS FOR TREAT- ING THE INNER SURFACE OF TUBULAR BODIES WITH BLASTS Wilhelm Eckler, Altona, Germany Application August 31, 1933, Serial No. 687,675 In Germany October 30, 1931 12 Claims'.

It is known to remove from the inner surface of tubular bodies, for instance iron tubes, the eventually adhering hammer-scale or vthe like, or to coat that surface with a certain substance or composition, by subjecting it to the-action ofan appropriate blast which may be, for instance, a mixture of sand and compressed air or a liquid mixture or, perhaps, a liquid metal, thefrespective metal being projected or flung against the sur-l face to be treated by means of a fluid under pressure, especially compressed air, as already mentioned. The respective blasting substance or mixture is conducted into the tubular body through a pipe located within that body and havl5 ing at its end an angular nozzle and being continuously rotated while the acting material is driven out through s aid nozzle against the surface to be treated, the tubular body being at the same time moved axially and care being taken that the distance between the axes of that body and of said pipe remains unaltered.

My present improvements in that method and in the means for carrying it out consist therein that, firstly, the tubular body, the 'inner surface 2 5 of which is to be treated, is rotated besides being axially shifted, secondly, that body is given an inclined position while being moved in the twofold manner mentioned, and that, thirdly, the inner supply pipe for the blast material is no nore rotated, but is and remains stationary.

This arrangement and manner of operation constitute an important progress in the art. With the known apparatus the tubular body is in horizontal position. The pipe supplying the blast material is provided with brushes contacting with the inner surface of the hollow body and removing from it the hammer-slag or the rust or the dirt that has, perhaps, adhered to said surface, as'yvell as particles of the eventually used s olid 4o blasting material, for instance sand grains, the respective particles being then further removed and carried away by means of `a current of air. This is effected, however, not simultaneously with the blasting procedure, but thereafter, from time to time, inthat the means therefor are separate from the blasting means; they do not form a unit therewithl Matters are otherwise with the present inven- 4 tion; It is important forthe efliciency of the 50 method that the particles separated from the inner surface of the hollow body, and those employed for this purpose, are continuously, quickly and completely removed from the hollow body treated. 'Ihis useful effect is obtained by the rotary motion of that body and its voblique position, as well as by making the inner supply tube stationary, so that the nozzle extends continually in one and the same direction.

An improved device for carrying out the improved method is shown diagrammatically and by Way of example on the accompanying drawing on which Figure 1 is partly (upper half) a vertical longitudinal section through, and partly (lower half) a side-view of, an apparatus designed according to this invention. Figure 2 is partly 65 (upper half) a transverse section through, and partly (lower half) an end-view of, said apparatus; and Figure 3 is a representation similar to Fig. 2, showing the blasting pipe (2) in an eccentric position relatively to the tubular body or tube (1) just'being treated.

In the example shown the hollow body is a co paratively long and comparatively narrow tube 1, and it is assumed that the inner surface of this tube is to be freed from adhering hammer-scale. Normally centrally or axially in the tubel is located a pipe 2 for the supply of the blasting material or mixture, for instance sand grains and compressed air, this latter tearing then the sand With it and the mixture leaving the pipe 2 through 80 the oblique nozzle 3 .which directs it against the inner surface of the tube 1. This tube is supported on rolls 6 and 6a, of which the rolls Gare aixed to a shaft 'Iv and the rolls 6*I are a'ixed to a shaft 7B. The two shafts are supported in 85 bearings 8 secured to a. plate 9 having downwardly extending lugs 11 from which extend forth pivots 14 bearing running rolls 10. These rolls run on rails (not shown) and these parts are arranged somewhat oblique, as appears from the acute angle between the full line 13 and the dotted line 13. 'I'his oblique arrangement is a particularly important feature of the invention.

The blast pipe 2 is provided with circular brushes which may be designed, for instance, 95 either as shown at 4 or at 4a in Fig. 1. 4 is a. cylindrical brush that is equipped at one side with a disk 8 consisting of a soft, yielding, elastic material, as for instance rubber and serving also for removing particles of hammer-scaleetc.v from the inner surface of the tube 1. If the carriage 9 with all members, including the tube, is moved in the direction indicated by the arrow 12, quasi up-hill,`

the separated particles do not take part in this movement owing to the oblique position o f the tube 'and the rotary motion of the same. The separated particles are retained on the bottom of the tube by the brush and the exible disk and arrive finally at the end of the tube, that is to say, the end of the obliquely upwardly moved tube `and subjecting it interiorly to arrives finally where there are said particles, and when then the tube is withdrawn from the apparatus, the said particles can be removed, as will be clear without a further explanation.

The same result can be obtained with a multiple brush like 4B in which the bristles of the two (or more) brush bodies are so arranged as to form screw-threads, as shown.

J 'Ihe brush 4, or 4a, may be a plurality of the one or the other, serves at the same time for supporting the blasting pipe 2 in the tube 1. It is, however, not indispensably requisite that the pipe 2'is arranged centrally in the tube 1, as in Figs.

l., and 2; it may as well be arranged eccentrically,

. The shafts 7 and 'l are rotated by an electromotor (not shown) which may be used also for moving the carriage 9, 10, 11 for which purpose then, of course, suitable transmission means are provided. I'he motor may be located upon the table 9 of the carriage. and connected with the source of current by a iiexible cable.

Besides with the means for removing hammerscale or the like from the inner surface of the tube,-the apparatus may also be provided with means for removing undesired particles also from the outer surface of the same, the inner and the outer means operating then simultaneously so that the tubular body need be passed through the apparatus only one time in order to be cleaned at its inner, as well as at its outer side.

1. 'I'he `method of treating the inner surface of tubular bodies with blasts, consisting in giving the tubular body an.v inclined position, moving it lengthwise, rotating it at the same time, the action of a stationary blast.

2. The method of treating the inner surface of tubular bodies with blasts, comprising giving the tubular body an oblique position, moving it axially, rotating it at the same time, and subjecting its inner surface to the action of a stationary blast directed in oblique position against the inner surface, substantially as set forth.

3. An apparatus for treating the inner surface of a tubular body with a blast, comprising, in

' combination, means for supporting the tubular body in an inclined position, means for moving 't lengthwise, means for rotating it at the same time, and means for directing a stationary blast against the inner surface of the tube while it is being moved lengthwise and rotated.

4. An apparatus for treating the inner surface of tubular bodies with a blast, comprising, in combinaton, means for supporting the tubular body in lan inclined position, means for moving it axially, means for turning it at the same time, a stationary blast pipe extending into the tubular body, and an angular blast nozzle at the free end of said pipe.

5. An apparatus for treating the inner surface of tubular bodies with a blast, comprising, in combination, means for supporting the tubular body in an inclined position; means for moving it lengthwise; means for rotating it at the same time; means for directing a stationary blast against the inner surface of the tubular body while it is being moved lengthwise and rotated, and rl means for removing from said surface the particles adhering to it.

6. An apparatus for treating the inner surface of tubular bodies with a blast, comprising, in combination, -means for supporting the tubular body in an oblique position; means for moving it lengthwise; means forrotating it at the same time; a stationary blast pipe extending into the tubular body; an oblique blast nozzle at the free end of said pipe, and means attached to said pipe and adapted to remove from said inner surface the particles still adhering thereto. Y

7. An apparatus for treating the inner surface of tubular bodies with a blast, comprising, in combination, means for supporting the tubular body in an oblique position, moving it axially and rotating it at the same time; a stationary blast pipe extending into the tubular body; an angular nozzle at the free end Vof said pipe; a circular brush attached to this pipe and contacting at its circumferential surface .with the inner surface of the said tubular body, said brush supporting the blast pipe in the said body. 110

8. An apparatus for treating the inner surface of tubular bodies with a blast, comprising, in combination, means for supporting the tubular body in an inclined position, moving it axially, and rotating it-at the same time; a stationary blast pipe located 4within thetubular body; a blast nozzle at the free end of said pipe; two circular brushes attached to the blast pipe remote from one another, one of said brushes being located adjacent to the blast nozzle, substantially as set forth.

9. An apparatus as specified in claim 7, comprising, in combination with the circular brush, a yielding disk also located on the blast pipe and contacting at its circumference with the inner 125 surface of the tubular body, for the purpose set forth.

10. An apparatus as specified in claim 7, comprising, in combination with the circular brush, .a rubber disk also located on the blast pipe and 130 contacting at its circumferential edge with the inner surface of the tubular body so as to wipe it, substantially as set forth.

11. An apparatus as specied in claim 6, in

, which the stationary blast pipe is arranged eccentrically in the tubular body. 12. An apparatus as specified in claim 7, in which the stationary blast pipe is arranged eccentrically in the tubular body and the circular brush is shaped accordingly.

WILHELM ECKLER..

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